Mixed Unleaded?

**denis_8th** · February 26th, 2009 11:02 AM

Hi. I am kinda new here, and I need information. Hope you can help.

Suppose I loaded 20L PETRON xtra UNLEADED in my engine. And I used up half of them (I still have 10L) and decided to fill my tank again. Is it ok to fill it with other unleaded products like -- SHELL unleaded, or E10 unleaded (car compatible up to E20), or gas with different octane ratings? Or should I empty my tank first? Would there be an effect on the engine if the petrol mixed? Thanks.

Thank you.

**1D4LV** · February 26th, 2009 11:09 AM

Originally Posted by denis_8th

Hi. I am kinda new here, and I need information. Hope you can help.

Suppose I loaded 20L PETRON xtra UNLEADED in my engine. And I used up half of them (I still have 10L) and decided to fill my tank again. Is it ok to fill it with other unleaded products like -- SHELL unleaded, or E10 unleaded (car compatible up to E20), or gas with different octane ratings? Or should I empty my tank first? Would there be an effect on the engine if the petrol mixed? Thanks.

Thank you.

no problem with that. but....
do not mix non-E10s with E-10s. although i do not see any issues with that, may mararamdaman kang significant changes sa acceleration.

**Dakila7** · March 19th, 2009 07:53 PM

Originally Posted by 1D4LV

no problem with that. but....
do not mix non-E10s with E-10s. although i do not see any issues with that, may mararamdaman kang significant changes sa acceleration.

mixing regular unleaded with E10... magimprove ba yung acceleration o will it be the other way around? TIA

**hominid** · March 19th, 2009 08:06 PM

Originally Posted by 1D4LV

do not mix non-E10s with E-10s.

???

Non-E10 + E10 = E<10 which is still better than pure E10 in terms of power.

Even unleaded and premium can be mixed, lol!

**batangmahal** · March 19th, 2009 10:08 PM

Originally Posted by 1D4LV

no problem with that. but....
do not mix non-E10s with E-10s. although i do not see any issues with that, may mararamdaman kang significant changes sa acceleration.

i did mix before... ala naman gaanong masyadong changes.

**meledson** · March 20th, 2009 01:50 AM

E10 is unleaded gas blended with ethanol at 10% by volume. So mixing E10 ang non-E10 fuels is no problem. Lalo na if you are using an EFI engine

**duskylim** · March 23rd, 2009 10:52 PM

Dear Sir:

What distinguishes E10 (or E anything for that matter) is a small amount of ethanol (in this case 10%, hence the name E10) added to the gasoline which raises it's octane rating and (depending upon it's source) serves as a bio-fuel.

From a fuel point of view, ethanol, C2H5OH, is in some ways not as good a fuel as gasoline,

- it has a lower heating value for instance (i.e. less energy per unit weight or volume), which usually means less power and fuel economy,

- and it maybe incompatible with some seals and gaskets in your engine and fuel system (but since you can run up to E20 that's a moot point);

but in some other ways also is a better fuel;

- it has a higher octane rating (resistance to knock) which allows for more spark advance or higher compression ratios,

- it burns cooler with a non-luminous flame, resulting in lower engine temperatures, better cooling, higher-efficiency burning;

- it is very clean-burning, essentially forming no soot (black carbon) during combustion, while forming much fewer pollutants than gasoline.

But the greatest drawback in adding ethanol to gasoline is not just issues regarding the environment or performance, it is that ethanol is HYGROSCOPIC (water-loving).

In PROLONGED STORAGE, (several weeks) exposed to the atmosphere, the ethanol will tend to absorb moisture from the air.

To mix well with gasoline, ethanol has to be ABSOLUTE (water-free), as it absorbs more water, it tends to separate from the gasoline.

Over a period of time what happens in your tank is that the alcohol that has absorbed some water tends to separate out a little leaving less alcohol mixed with the gasoline.

If you could peek into your tank you would see 2 liquid layers forming, the 1st, is the uncontaminated gasoline-alcohol mixture floating on top and the
2nd, is the contaminated water-alcohol with a lot less gasoline mixed with it on the bottom.

The water-contaminated layer is below the uncontaminated layer because water-alcohol is denser than gasoline-alcohol and will sink to the bottom.

This separation gets worse over time, with the 2nd layer constantly growing. Also because it now has water, it can now absorb any water-soluble materials that have gotten into your fuel tank.

If you know your fuel tanks you also know that fuel is drawn from the bottom of the tank and not the top. So the tendency is for the fuel system to suck in the contaminated layer first!

It first hits your fuel filter before being sent to the carb/injectors.

So here's a little tip for all you E10 user's out there:

CHANGE YOUR FUEL FILTER REGULARLY!!!!

Best Regards,

Dusky Lim